By James W. Harris
A Practical History of Measurement, Communication, Standards, Automation, and Control
The International Society of Automation (ISA) is celebrating 75 years as the leading authority in automation. As an ISA Fellow for 15 years, I offer the following comments about the past and future of measurement, communication, standards, automation, and control.
The process under control can be very simple (i.e., opening a door or setting the temperature in a kitchen oven) or complex, with multivariable matrix optimized functions (i.e., crude oil refinery production flow and temperature controllers). ISA has been involved in making all these systems run at peak performance with high levels of reliability, availability, and safety.
Some things have changed over the past 75 years, while others are surprisingly still very much the same. Flow measurement continues to use a handful of technologies. Orifice plates, venturi, vortex, and turbine meters are still the primary meters applied in oil refineries. More recently, some applications have been improved with the application of Coriolis, ultrasonic, and magnetic meters.
Looking to the future, it is likely that flow will continue to be considered a primary variable worth measuring. However, it could be that more and more flow information will be available using simulation and modeling to provide the missing information when a direct measurement is not available. No simple flowmeter exists for applications of two-phase flow; therefore, it is generally estimated using simulation. Direct measurement requires an elaborate system to separate the two phases and measure them.
Similar situations exist with pressure, level, and temperature measurements. Using simple physics-based applications and translating the reading to a primary process variable within a transmitter to communicate the variable is now accomplished with a microengineered mechanical system (MEMS). This has improved the accuracy, reliability, and other performance characteristics of these devices. A continued focus on key performance characteristics along with lower power and weight will continue. The other changes have been to move in concert with changes in the communication protocol used by automation systems.
ISA has been leading the evolution of the communication protocol for the past 75 years. Pneumatic controllers were very common in 1945. Many significant advances have occurred. These will continue, while moving towards a fully wireless communication world. Information is now able to be delivered anywhere on the planet virtually instantaneously. The problem used to be how to communicate the most recent information to the control system, and now the focus is how to only communicate the required information.
Alarm overload is also a prominent area of communication problems for operators in 2020. As more and more applications are available from the cloud or some other virtual location, personalizing the delivery of information is a key area to establish best practices. This will enable the receiving party to easily take any action required—even if it is to do nothing.
ISA is a leading authority in the area of personalized data on many fronts. ISA symbology makes it very simple to share the process requirements between the system design and the end user. These symbols are then easily translated to the HMI (human machine interface). In 1945, these were likely vista-green wall boards of the process with the single loop controllers embedded in the wall. Now the display could be a heads-up image that is nearing the holograms of Star Wars and other popular cultural views of the future.
As with many things done by ISA, symbology is backed by many different publications and ISA standards. Standards available from ISA cover alarms, safety applications, control valves, communications, cybersecurity, and many other topics. These standards provide an abundance of information. The addition of specification documents to focus the information flow from designer to vendor and end user is another area for ISA to celebrate as a beneficial achievement.
Fully automating an assembly line or manufacturing factory is not the final step. Advancing manufacturing via robotics and data-driven inventory control is the next phase. The days of making “any color car as long as it is black” are over. This is no longer a competitive approach to manufacturing.
In many industries, the factories constructed today are very flexible. They need to be ready to make a product that has not even been envisioned yet with very few capital changes. Oil refineries today are designed to produce different fuels (gasoline, diesel, jet, etc.) and/or different petrochemical products. Additionally, these refineries are looking at alternate feedstocks and power sources to efficiently deliver the products. The oil refinery can make all these adjustments with the help of automation.
Engineering tools have evolved beyond the pencil, paper, slide rules, and chalk boards that were common before computers. Currently, process models can be viewed on a laptop, tablet, or handheld display. This is also true for equipment sizing and engineering tools for flowmeters, control valves, and other components. With spreadsheets and other customized tools, the engineer can evaluate multiple different operating conditions. These computer tools became available from industry collaboration via ISA—and other organizations—bringing together experts to create the necessary standards.
The advent of engineering tool automation has also improved design information data flow. When pencil and paper were used to fill in a specification sheet, the current copy was kept in a central files area. All other versions of the documents were considered out-of-date. Changing a control valve required confirmation of the documents in central files with the installed valve in the field. Once this was clarified, the engineer could evaluate the new operating conditions with the vendor’s handbook. A current catalog could be used to identify the best option for upgrading the valve.
Now, all these steps can be done online. A digital twin can even be used to evaluate the operation with the existing valve and any alternate valve being considered. Additional information such as diagnostics of valve performance can also be useful for the evaluation and will be available from the online maintenance records and real-time operating historian. This provides opportunities to estimate the end of life for equipment and adjust operations to retain acceptable performance until critical parts can be replaced.
Asset management has advanced, as noted above. In addition, the use of digital circuitry in transmitters, controllers, and positioners has reduced variability in operations while also improving the reliability of all instrumentation used in industry today. Software can now be used to adjust the calibration of hardware installed in the field from anywhere. Seventy-five years ago, these adjustments required a visit to the device—and in many cases, taking the device back to the instrument shop where it could be properly adjusted before returning to service.
ISA has had many substantial achievements during the past 75 years. The future will continue to offer challenges to solve using our collective expertise. By remaining grounded in the fundamental areas of measurement, communication, standards, automation, and control, ISA will remain the leading authority for automation.
A shortened version of this article was published in September/October 2020 InTech—the ISA 75th Anniversary Special Edition.
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About the Author
James W. Harris is a 2005 ISA Fellow.